Mechanism of Inhibiting Stress Corrosion Cracking of 18-8 Stainless Steel in MgCl[sub 2] by Acetates and Nitrates

Abstract

Modest additions of sodium acetate, nitrate, iodide, or benzoate to test solution boiling at 130°C are found to increase resistance to or inhibit stress corrosion cracking of 18‐8 stainless steel. The critical applied potential in solution (−0.145v) above which, but not below, cracking occurs is shifted in the noble direction by extraneous salt additions. When the shift exceeds the corrosion potential for 18‐8 in the same solution, cracking is apparently inhibited. On the other hand, salt additions, e.g., , which shift the corrosion potential in the noble direction may induce or accelerate stress corrosion cracking.